Despite significant advances over the past three decades in our understanding of the implicit dangers in ad hoc psychometric procedures, some important questions remain, particularly as regards the nature of the underlying reasoning process by which subjectively meaningful theoretical impressions are formulated and expressed. The present article seeks to address this issue, with particular attention being given to the distinction between demonstrative and dialectical reasoning. Evidence is offered to show that, at least under certain conditions, intuitive psychometricians formulate and express theoretical impressions on the basis of a reasoning process that is essentially dialectical in nature. Some major implications of this point of view for the study of personality theory are discussed. The limitations of the evidence presented, and the need for further research, are forgone.